It's a serious question. When I say bath water I mean that my pet is going to be in the tub and I am going to get water from it and sell it. I'm only selling within the USA via USPS. Will I have any problems with shopify, stripe, or paypal?
You can review the forbidden products here:
Ted here from Shopify, thanks for reaching out to us!
As @PremierStores mentioned, as long as the product complies with our Terms of Service (here) then you are more than welcome to sell it. We would always recommend making sure that your products also comply with your payment gateways Terms of Service too. I was chatting with the team and I can confirm that if you are eligible to use Shopify Payments, then you can sell bathwater in theory, yes. As long as the product does not claim to have any health benefits; as this can be then be counted as a Pseudo parm product as outlined here in our Shopify Payments Terms of Service. Each payment gateway provides its own Terms of Service, so you would need to contact their customer support directly for more info.
If there is anything else I can help you with, please let me know, I'm happy to help!