I need to a little more elaboration on the methods of stripping you are considering. Well the answer to the first part of your question is a simple YES.
If you are asking whether you can remove the cells from the surface of the tissue culture dish without using trypsin, there are at least 2 other ways: scraping them off or using EDTA. To use EDTA, first rinse off the medium using citrate saline, then soak the cells in citrate saline containing 0.5 mM EDTA for a few minutes. This may cause the cells to slough off, with a little help from mechanical agitation.