which glue to repair kids floaties?

I have some of these inflatable kids rubber rings, toys etc, I presume made of PVC, with little holes in them here and there, leaking air

some rips are close to the seam so I cannot put on a sticky patch. I think it is possible to put a "glue" on top of the little hole to seal it (without a patch). I read about MEK glues, but MEK is a solvent right? How can it glue anything?

What kind of glue would you recommend for this kind of repair? Must be

• water resistant
• stretchy (to resist inflation)

Another concern is the cost; these toys cost $5 or less so I don’t want a glue that costs more than the toy! I would also prefer something that lasts for a few months once opened.

thank you for your recommendations
Nikos

PS. would plain superglue work on a small hole without a patch?