I use a dab of vasaline which typically makes a great seal

So far these produce better sound and (with the large tips) provide a better seal than the Swimbuds

the seal isn't great so water tends to get in muffling the sound; the coiled cord was initially too short and pulled them out but is better now that I stretched them.

Sound is good on these if you achieve sufficient airtight seal on your ears.

Works as