"Can I use a household iron instead of a laminator?"
It's not just HEAT to make Toner Reactive Foils (TRF) transfer properly to a laser printed image. It also requires a lot of PRESSURE at the same time to affect fusing the foil to the toner printed image. Not to say that it can't be done, which it can, but the problem is how much pressure can YOU deliver. Even putting your entire body weight over the iron - leaning on the iron with feet off the floor - that's only a few pounds of pressure per square inch (PSI), and you can't just increase the temperature to compensate for low delivered pressure.
If the pressure is too low you can get areas of the image of the image where the foil didn't fuse so that after you peel off the foil, you can get raw toner areas that the foil didn't transfer to. Further, you can't go back and try to fix the bad areas because the good transferred foil around the bad area(s) is physically higher than the surface of the toner image so the foil can't get down to the level of the toner. You basically just throw the image away and try again which is pretty frustrating. The only acceptable method is to use any modern pouch laminator.
All modern pouch laminators have heated rollers to deliver heat and a LOT of pressure... into the hundreds of PSI because of the pinching of spring-loaded rollers to deliver a realized - linear applied pressure. Ok, so let's agree that a laminator is the way to go. It doesn't stop there, unfortunately. These pouch laminators that you see in all office supply and big-box stores are not all equal in performance. There are 3 ratings by the laminator manufacturers: 3~5mil, 7mil and 10mil. The "mil" refers to how thick of a plastic pouch the unit can melt properly to seal what ever was being passed through the unit. You will see this "mil" rating/capability on the box of any unit you see in the stores.
"So, can I use one of those ~$20 super-cheap laminators from big-box stores like WalMart®?
Sure... IF the paper you're wanting to foil is a very light-weight paper, like conventional 20~24lb regular printer paper. The thicker, heavier, textured papers require much more heat and pressure. which is why if you're going to buy a laminator, don't put a 'roof' over your ability to handle the heaviest of specialty papers. We've always recommend the most powerful '10mil' type laminator as they can handle any weight or texture of paper, but if you look at the prices of these '10mil' laminators in your local office supplly store, you'll easily go into sticker price-shock with prices ranging from $300 to $2,000! There are, however, two affordable alternatives to these expensive big brand names from Akiles®, Fellows®, GBC®, Royal-Sovereign® and Swingline®... the APACHE "AL-13P" (~$100) and the TAMERICA "SM-330" (~$140).
We did a head-to-head comparison on these two units in 2016 and as powerful as these units are, found some very big differences. We looked at design, quality, construction and safety. Both are made overseas (as are the big-brand names). The APACHE is a Chinese design, where the Tamerica is a S. Korean. Even though both manufacturers do a great job of foiling, handling the heaviest of papers, we found the Tamerica unit to be far superior in every category of manufacturing.
From our review, we decided to carry the Tamerica SM-330 and have had great responses from our customers. It's also important to note that the APACHE unit does need to be opened up to make spring adjustments to its roller-pressure design. The TAMERICA with its better overall design that never needs adjustment and has overheat shutdown protection. As for "safety" the APACHE does not have overheat protection! This was of very high concern as these units run upwards of 300ºF so we'd recommend putting a cheap smoke-detector above your work area with this unit. Yes, there's normally a $40 difference in price, but all-in-all, a far better design. The old adage... "You get what you pay for" is very true in this case. If you live outside of North America on 220v power, these units will not work (and shippnig would be expensive). Look at our discussion on how to find the best 10mil laminator under the menu heading "TECH INFO" > Laminator, half way down the page.