I have been using washes based in Tamiya acrylics ( and oils too of course) over chrome surfaces during years and never ruined them.
Probably your are experienced some of the following problems.
1) You mix Tamiya with other solvent different that X20A which is isopropylic alcohol.
2) You are using Gunze acrylics, or other clear paints. the Gunze thinner is a hard solvent, even the one provided for acrylic paints.
3) You are working with old chrome parts. Sometimes the parts are so old or the chrome is so bad that just is removed with soapy water, it happened to me few times.
I use smoke washes over recessed chrome parts, to give volume, and never had that problem, I always use X20A, don't use ethylic alcohol or water as diluter.
Clear paints are useful too to tint windshields, it must be done from inside airbrushing very diluted paint, the more paint you apply the darker the surface will be.
Mario Covalski
Editor
http://www.modelersite.com