I don’t know about other sealants but Suzuki actually recommended that Barrs leak be added to radiators in the 80’s. As you say, glycol is very ‘searching’ so leaks were always a problem on both my GT750 and RG500. The (stock) radiator on my RG500 is known to be marginal. My bike has a Stage 3 tune and puts out 100 bhp at the rear wheel. I’ve used all that power at quite a few trackdays so clearly not suffered from clogged radiator cores. Thats good enough for me 😛
Other RG500 owners have used ‘water wetter’ with good results but I’ve never felt the need.