How to completely remove cells from surface - (Oct/17/2012 )

Dear Guys,
If I am culturing my cells on certain surface, how I can make sure that the surface is clean again
what I do:
I remove cell remaining using Trypsin EDTA.
Then I immerse in hot acetone for 10 min
the immerse in hot methanol for 5 min

Any suggested protocol to clean or remove surface for cells??
Thanks in advance

Physically, by scrubbing it with something? A cell scraper?

Actone and methanol will precipitate proteins onto the surface. To be truely clean you will probably need to acid clean the surfaces.

Thanks guys for ur suggestion but I cant use surface scrape or acid as it will ruin my very senstive surface.
what I really did and it worked perhaps it helps someone else:
I cleaned my surface with Trypsin EDTA, the put it in hot acetone (pure) directly.
unfortunately, acetone made some precipitation on my surface.
so I had to wash it several times with hot ethanol (99.5%) and several sonication cycles (30 seconds), but it was unclean.
so I left my surface immersed in clean ethanol for 48 hrs, then here it is very clean and shiny as I got it.
so I believe if i tried to wash it using milli-Q water for several time before acetone, I can avoid this sudden protein precipitation , then acetone and ethanol steps