So you are one of those guys who dig up antique posts. :-)
Sorry, I don't think micowaving pots will help. I have, on a few rare occasions and with some patience, managed to salvage a few pots of dear but OOP acrylic colours by disolving the contents in acetone (nail polish remover), drain it, and then re-medium it by adding water and a wollop of PVA (firm stirring required). Doesn't always work. I think most of the time regranulation of the cloggy bit are required anfd that aint worth the trouble.