You might want to go through these threads

Are you totally sure you had mealies? They eat live tissue so I don't think removing the old leaves will solve your issue. Also I would just leave them be, I think it'll be more harm disturbing them than good.

Hmm, I knew they ate new growth but I always thought it was the dead or dying that attracted them in the first place. Both times I dealt with them they made a home for themselves in a “tight” succulent that had a dead leaf I didn’t pull. First my Gasteria then the Haworthia. It’s definitely mealies. White with the web stuff. I’ll have read up on what exactly attracts them I guess to see if there is another common denominator with those 2 plants. I ended up removing my Echeveria seedlings and putting them in their own pot so the Lithops can do their thing now and I won’t have to worry about the Echeveria. I’ll check out the threads you linked. Thank you!