Do try to restore the system file and database first as you may only have corrupted some of the playstation firmware and these will restore the ps3 to uncorrupted status.
You will see it as soon as you get down to th two chips it will be a white powderish substance i suspect. Heres a vid i found to help a bit, though it doesn't show the removal of the thermal paste, you can buy quality thermal paste like artic silver 5 on amazon for less than a tenner and it works on all computer heatsink products.
To removal the thermal paste your best using some sort of rubbing alcohol like acetone, it does come on some monitor wipes thats what i used
whilst your inside the ps3 it gives you a chance to give it a good clean i removed a pound of dust (i'm not kidding i weighed it) mostly crammed in the power supply, taking it apart is alot like taking a laptop apart just easier; because it has screw point marks on each level of construction.
Bad news here though, if it freezes loading games: it may be the bluray telling you it's dying, i hope not as this is an expensive repair even if you do it yourself as the cost of a new bluray unit can be £60 or more, It is a git to fit because of the attached logic circuit. When it happened to me i sent it away for repairs to
http://www.consolewerks.co.uk/ they sorted it for 79.99 but the postage was at christmas time and cost me a further 20 quid