Wetfastness will be a problem for strong/bright colours wherever you buy them from.
More so if the chenille has been hand dyed as the fixing process cannot be accurately controlled in the same way as in a commercial dye machine with precise plc control and high temp capability.
Further, it depends on the original substrate (Nylon chenille, Rayon chenille, presence of flash materials etc). Many of these exhibit poor dye take-up in the first place so therefore have low fastness, especially when wet. Also lightfastness is a problem too – bin the clear lid flybox and get a covered (dark) one!

Dyestuffs used may be acid, reactive or for polypropylene, high temp (130deg) disperse – so the best fixing required can be different.
Sorry I can’t be much help on the hand dye stuff but I know there are others on here who do that and so may be able to help more.