If you cant fix the problem by just blowing it off then its time to get it repaired or a new one. I dont care how many people say its safe to put crap on the lens there is no way I would do anything to make the problem worse by letting any kind of liquid dry on the lens.
yes, i actually do this about once a year, it works quite well. Rubbing Alcohol isnt like water, it wont ruin your lens, it will dry without leaving smuges and it cleans quite well. You just have to make sure that you are careful while doing it. I assume that by this point you have nothing to lose because if your ps2 doesnt work in the first place it isnt like it can get much worse, so, try the rubbing alcohol thing and if it doesnt work then you can replace the ps2.