Wanted to see if it could be done. Looks like it can.

A few iterations, vase mode was not reliable enough when printing, given the shape so this is a normal print, 0.2mm layers, two perimeters, 0.6mm width on a 0.4mm nozzle, 1.06% flow(normal for TPU for my MK3S+). No supports required.

The clamp is PETG here - it's stiff, but it needs to be to keep watertight, which it does surprisingly well. It is possible to clamp it crooked and have a drip of leak but I think even that will stop as the TPU squishes together over a bit of time.

Can probably scale from 66% - 150%, but outside that, the wall width is probably less than ideal, so likely better to modify the design files, or if you aren't into that, maybe ask and I'll see if I can come up with the size you need.

.Step / .f3d files attached for mods.