My new recirculating tub tester. Occasionally I come across a recirculating tub with no drain stopper. I started bringing a small stopper, but I was then reaching through 6-12” or more of water to drain the tub after testing. Attaching a marine key float solved the problem.
Even if they had a drain stopper you would reach through a foot of water as most are push on/push off stoppers. You might want to carry an old towel in your bag.
A towel is a must, but I’ve been using the “grabber” I carry to lift the float on a sump. It’s long and rigid enough to activate a functioning push type drain. I also use it to turn on those pesky showers that have the valve on the back wall. I’d rather wipe off my tools than me, especially in winter.