powerburst and citra boost gets most out for me.
i have rust remover for rust, obviously

i have sod mets for tea coffee red wine and ominous coloured stains
and i have pog for paint
thats about it really, only struggling with chewing gum at the moment........
did have hydramaster OJ for that but 1) they don't seem to stock it anymore and 2) its prone to bitumen bleed if used incorrectly.
have tried other chewing gum removers but not very good, looking for one that works really well but without effecting bitumen!!!