Re: Rubbing alcohol . . .
Most of the proprietary head cleaners (and many other electronic cleaners) were chlorofluorocarbons (CFCs) such as some of the older DuPont Freon products. Pity CFCs are not still available in small quantities for these sorts of uses. My stash is slowly being used up, apparently never to be replaced. Last I knew, CFCs and HCFCs were still in use for vapor-cleaning electronic assemblies, in closed solvent-recovery systems.Many professional quality tape deck manufacturers recommended isopropanol or their own branded proprietary cleaning kit.