About 30 minutes. Another option would be a feeding dish and pipette.
They're not going to rot - you should have a few detritus worms in the substrate; something will find them.
A fantastic investment my friend.
Thanks - yeah I think the feeding dish is going to be the way forward - I don’t always have enough time to prep half an hour in advance (three kids with busy evening activity schedules!).
I do have a nice dish with a tube that I use for the shrimp currently, so I can use that: