Dust on sensor?

I've been reluctant to switch to DSLR because of the potential problems
with dirty sensors caused by the ability to remove the lens.

Is this a real problem with DSLRs, or not as bad as it seems. It
appears that Canon recommends use of a hand-held blower for dust
removal, but I wonder whether that actually works. Dust is often
tenacious and bonds itself to surfaces in ways that are resistant to
simple blowing. Maybe the best example is my eyeglasses. Once they
get dusty, only windex will clean them thoroughly.