Sometime ago i was repairing my brotherīs nikko RC toy car. And i found that all the electronics where dipped is something like paraffin. I had to resolder wire and i was able to do it trough it ...
Some waxes have a melting point suitable to survive the working temperature of a MMM and yet allow to melt it without desoldering a component or even soldering trough it...
http://www.frankbross.com/
this guys should have a suitable wax..