Welcome aboard, Jean.
Yes, some tips. You usually have to wash with the sponge more than once. We do it twice at a minimum. Even then it's sometimes necessary to go back and clean with vinegar in a couple days.
You should never have to mop 5 or 6 times. Moping is something you do after the grout has been cleaned and sealed.
I'm going to move you to our grouting and cleaning forum. You'll like it over there.