Making the inside of sandals less slippery?

[fernz]

I don't know if it's just me but I seem to find the inner soles of most sandals can easily become slippery if my feet sweat at all or if it's raining. Does this happen to anyone else? It affects any sandals made of smooth leather.

I have a pair of Saltwater sandals I love but don't understand how anyone can wear them in the rain because my feet just feel like they are sliding around in the sandals.

Is there something I can stick onto the insoles? I've had a look at a few things on Amazon but it's hard to tell how good they'd be or if they are comfortable.

I mainly live in Birkenstocks so not a regular issue for me, but I have experienced this when wearing wedges and similar. I found that roll on or stick deodorant applied to soles of feet worked a treat! Not sure if it's something I'd want to do every day, but for the odd hot day with particular shoes it's fine.

I only wear leather sandals and this never happens

You could try rubbing them with sandpaper?

I had a really nasty fall when I was wearing leather open sandals, walking the dog, and there was a sudden downpour. Massive blackeye and lucky not to end up in A & E (although I should have gone). Now I avoid wearing that type of sandal, but even with other types if I think there may be a problem I scour them with a razor, both underneath and on the sole.