ps2 lens starting to not read games

[cv65user]

i have a ps2 black big type, version 7 i belive since it says spch 30005?

its not starting to read dvd games
plays blue cd games -some snooker game
plays sonic heros - its a silver back so i presume dvd
audio cds ok
dvds ok

but it doesnt play street menance (silver base) stays on blank screen after splash screen, and getaway (silver base) loads trailer bits but when i press start it just says loading forever and u can hear cd is just spinning

i opened it up but did not open the cd lens cover part coz i dont want to play with sensitve area yet (aint cleaned the lens with q tip yet). air dust everywhere, ran dvd lens cleaner kit 5 times (its a dvd with brushes on it). cleaned cds with wet wipe.

now it plays getaway flawlessly but still same problem with street menance and st menance cd is slightly scratched ...after the ps2 splash screen it just stays blank screen

- do i just use a cotton swap and wipe the lens and hopefully that should work??
- or do i wipe cd with toothpaste to hopefully grit smoother?