I handwash almost everything that says to dry clean only. The exception is anything that is lined. This is because materials, particularly natural and man-made, dry at different rates. It is the drying process where most of the irreparable problems occur.
Oh, well, let's face it. When I say "handwash" I mean I put it in a mesh laundry bag and put it in the washing machine. Yep. I use Johnson's baby shampoo. Then I air dry the garments--make sure they are dried flat.
If I am concerned about bleeding, I will handwash them in the sink. Use cold water. The caveat to this is that if the garments are bright colors there may be color run. If I had to clean such a garment, I would consult with an Hermes group to which I belong, because many women prefer to handwash their scarves, and they have a nearly fool-proof method for doing so.
Blends of synthetic materials are the hardest, of course, and should probably be dry-cleaned. The fact that some material just shouldn't get wet is probably true, and reason for me not to buy the garment. Once, the perspiration from my body caused the garment to bleed right onto my torso (a velvet top from Lord & Taylor). If I suspect a garment is that fickle, I won't buy it in the first place.