Personally, I wash my suits with the rest of my laundry, and dry them with it too. I’ve seen no ill effect of doing this, and I’ve been doing it this way for 4+ years with my most used suits. Cold wash/rinse, Arm & Hammer Free Detergent and color safe bleach, low heat dry, with an unscented fabric softener sheet. Only suits I had a problem with were metallic ones, and that was just my own stupidity, lost most of the color, so I now have a silver and blue splotched suit. I can do a list of fabric mixtures…might take me a few days to compile and might be more than what is readily available for zentai (i.e. slipping into cycling/surfing etc. country) AND some could be wrong. Only human etc.
I also don’t add any detergent because my washing machine has the odd effect of keeping some leftover detergent around in the pipes from the last wash, so they get a mild dose of it even without me adding any. Been doing this for years without issue, my first zentai (perhaps 7-8 years old?) is still as good as new. I have a question. When I take off my Zentai my nails looks black from the fabric and some of the coloring rubbed off on my face. Is this normal does every Zentai wearer go threw this? or is this Unicolor Zentai Suitsa bad thing? When the fabric is made and the color is dyed in, excess dye can stay in the fabric. That excess dye will come out the first time (or first few times) you wash the suit – or if you sweat onto it before washing that excess dye out! I had one plain black zentai which took several washes (maybe as many as half a dozen) before it stopped turning the water purple every time it was washed.