I put mine in the washing machine with my dirty work clothes and they come out clean on the other end.
Been on the same set of BDUs for... what, three years now? They look fine because I keep my kit clean. Believe me, I spend a LOT of time crawling around on my face so maintenance is key.
But yeah. Cold water detergents and never hot water. If you come in contact with one of those oil-based irritants, a light soapy mixture of water and Dawn or Sunlight dish soap (20:1 at most) will break up those oils right quick.
Age Verifier - Lower Vancouver Island
Brotherhood of Nod - Nod Prime || Vancouver Island Airsoft League - President