Leopard Gecko Incubation Help PLEASE

Hey guys, I was talking with a friend tonight who told me that their son has a leo that is nearing full term and close to laying her eggs. The mother and father are both albinos. They told me that the animals are "young", though I did not find out the exact age of either one. Here's the problem:
This will be the third clutch that this pair has produced, the last two both had 2 eggs. They told me that both clutches started out fine and then the eggs went bad at some point in development. They told me that they put the eggs both times in a separate, insulated container with a temp/humidity gauge sitting on top of a heat rock, kept the temp and humidity in the "proper" range and both clutches wound up shriveling and going bad. I was thinking that the fact they are using an insulated container sitting on top of a heat rock might be the problem, kind of like frying the eggs from the bottom. I told them they should probably pick up an incubator this time around. I know I should probably be bringing more info to the forum to give you the full scope of the situation, but this was kind of a passing conversation and I didn't really have much chance to pump them for all the details. Any info you can give me would be apprecciated. I would love for their son to be able to actually hatch out some leos this time around. Thanks.