Me dear old Grand Ma-Ma [may she rest in pieces] used to wash and re-use plastic bags until way past the stage they turned opaque, it takes a lot of washings b4 they turn opaque.You can also get vacuum sealers that work on special bags with a valve for the sealer and close like zip-lock bags. You can open them, reclose and vacuum again. The manufacturer says you shouldn't reuse them after putting raw meat in them, but I see no reason why not if you wash the insides properly.