Meindl's recommendation is to use an impregnation spray and wax after that - see attachment.
Same procedure should be good with any make, I would think.
Meindl SportWax happens to be my favourite wax, I like it enough to continue using it on whatever make my next boots are. In previous threads on this forum on the subject of treating boots, some members swear by Leder Gris wax.
EDIT: Sorry, there is no attachment, the pdf is to large. You should be able to find it or similar info online by doing a search.