
Well ... I wasn't going to suggest making your own, but the one I made for my dog for after hydrotherapy sessions was much admired by my dog and by other pool users! No, before you ask, I'm not in the market for making any more ... though maybe I should be?!
I seem to recall seeing someone's from Country Mun, quite a while ago, but that was a double layer towelling, with insulation between. Not sure if they still sell though.