Originally Posted by jgrebe
Actually the hose fitting on (my) eco-safe is 3/4 female hose thread (FHT) to a 1/4"male pipe thread ( MPT). Don't think you can buy a commercial substitute as a single fitting but should be able to rig up a substitute using several standard fitting. 3/4 FHT x 3/4 MPT + 3/4 x 1/4 bell reducer + 1/4 nipple. Or something similar
I have the same groover and I know the piece you mean. I second this response, a female hose to 3/4 female NPT adapter, then a 3/4 to 1/4 bushing, then a 1/4 NPT nipple would do it. The bushing would provide a place to grab with a wrench or pliers to thread it into the toilet cap, if needed.