Alcohol is ok, but I find naptha (lighter fluid) to be a much more effective
cleaner. You use it sparingly, and don't get it on any plastics, some don't
like it too much. The old beta tapes are probably the biggest problem,
finding new(er) ones would be a good idea. When the tape coating binders
start breaking down and the oxide sheds, the end is near. Transfer your
treasured video from the old ones and pitch them in the trash.
Regards,
Tom

you copuld try alcohol, some don't recommend alcohol but I
personally haven't seen it damage any rubber provide it's used
sparingly and excess is dabbed up.

(Anybody reading this with good or bad experiences with using alcohol
in this manner could perhaps enlighten me?)

good luck
Ben