I use Gorgomyte because it cleans the fretboard, conditions it, and polishes the frets at the same time. If it’s too pricey for you then use mineral oil from a drug store; lemon oil and some other fretboard conditioners are just scented mineral oil.
I would not use wax on rosewood because, as you already noted, it will glob up in every little pore and crevice. It might work for ebony though.