I know many people do this. A while back I heard an episode of Bike Shop CX (great podcast all about CX and gravel specific wrenching - imagine Car Talk but for your bikes!) with a Stan’s pro CX team mechanic talking all things tubeless. TONS of great info in that episode, but he specifically warns against using any kind of duct tape around the 52:30 mark here:
He does also note that for MTB tubeless things are a little easier and more flexible because of high volume, low pressure tires. But as you get into CX and gravel volume goes down, pressure may go up (depending on many things) and the tubeless setup becomes more susceptible to problems. And road tubeless follow all the rules and only use road tubeless specific equipment because that’s low volume/high pressure - the toughest scenario.
He’s not even specifically pitching Stan’s brand tape there. Just pointing out the problems with duct tape solutions - actually can be porous and leaves residue on rims. Also it will be thicker than tubeless specific tape, which can make mounting harder to impossible on some CX or gravel rim/tire combos.
All the tubeless tips in the episode start around 24:20 and are well worth a listen for anyone looking for tips.
Another good one in there? Don’t create your valve tape hole with a knife. It will likely cause a longer radial split in the rape right at the valve and that will forever want to leak. I’ve had this. Ever had a tubeless setup always wanting to leak at the valve? It’s probably that. You shouldn’t have to wrench on that valve nut - that causes more problems! (Roadside removal!)
My favorite in there? For rim/tire setups that are extra hard to seat (again probably more likely in CX or gravel) mount first with a tube to get the beads to pop and seat. Then remove tube from only one side of tire, leaving other bead fully seated, then you only have to deal with your pump/compressor seating one of the beads. Has helped me a number of times. Tight WTB gravel tires to name one.
As for sealant, I like Orange Seal Endurance because it lasts longer, is usually easier to clean up but still seals well. As others have noted it does clog valve cores though. I figure those are cheap/easy to replace occasionally though. When it’s hard to pump up your tire you’ll know it’s time!