Ordinarily, excess AS5 can be cleaned off relatively smooth surfaces with isopropyl and a fine cloth, maybe nylon stocking or a napkin.
If there are solder pins on small parts that have become contaminated I only guess that there's still some risk of conductive-material contamination if you can't reach every nook and cranny.
I once used an Arctic conductive epoxy, and got a little on the pins of a mobo chip for custom application of a small heatsink. I thought I'd cleaned it all before the epoxy set.
The motherboard continued to function normally, but eventually "went south" -- for any number of reasons which could include some residual epoxy contamination which wasn't visible to the naked eye. And my own naked eye isn't all that better for a good set of glasses . . . .