Yes - distilled water is a very powerful solvent compared to tap water - over time it will even eat Teflon off water heating chamber walls where water with dissolved minerals wouldn't touch it after years of use. Wal-Mart has 32 ounce jugs of 91% Isopropyl for a dollar. My favorite solvent is dry-erase board cleaner but it will strip the labels off keyboards, etc. but should knock down any smoke or other accumulations.
Take sharp clear macro photos or record every component number before starting. You might have big problems after trying to match values or specs if you don't (beyond the OEM relabeling)...
You have one good opportunity to get them clean; 'modern' electronics are NOW almost all water washable since the new VOC guidelines have specified warm water to replace the old flux cleaners, etc.. So on a your 10-year old unit you may have lost a few components already so go for it. Repeated drying cycles are bad if you use heat - kind of my personal opinion but you have a day or two of rinses and one good 12-hour bake then PCB lacquer. If you buy the electronics kind know there are a couple of flavors of it, I don't think you need the $25-a-can 20,000 volt dielectric stuff.
Beware the old leaded solder that's grown lead oxide crystals - no food or smoking when in the work area and do the work on a disposable surface with disposable supplies and don't be breathing the brush mist blah blah blah.
