I just keep getting people telling me i must be tired. Not even played for an hour. Don't think i've had one works project request from diving/hiding. Maybe i need to do it later in the day when more residents are around
It's actually better to do it when there are less residents around. The game randomly chooses a villager every few mins that will want to run up to you next, so if you've only got two outside it can only choose between those two.
Quick tip guide for best use of the diving trick:
1: Do a fresh load of your town, this'll reset the dumb "you look tired" message counter.
2: Fill your inventory completely with tools, flowers, shells and bits villagers cannot buy.
3: Do a quick run around your village to see which villagers are around and where.
4 (optional): If you want specific project requests you need to get your PWP from certain villager types. The best way to ensure this is to dig a run of holes around the villager that can give the project you want, making sure to also block any house or building entrances in that run so they cannot move from that area (give them room to move though, otherwise it seems to screw up).
5: Go swimming to the corner of the map (far enough away so you can't see land) and leave your character to sit there for 5 mins. Doesn't matter if you get stung by jellyfish, so just leave it idling.
6: Get back on land, walk in front of villagers until it triggers a run up event and talk to them. Rinse and repeat. It is still luck based so you could end up having to do this for 1-2 hours to get a PWP request. Keep in mind that after a while you'll stop getting any villagers wanting to speak to you, if this happens talk to any of them as they'll want to give the "get some rest" speech.
Sidenote (optional): When trying to get PWPs from a specific villager they will not always want to speak to you every 5 mins, if they don't just go swimming again without talking to them and they'll likely want to speak to you after another 5 mins.
Swimming isn't necessary, so anyone who doesn't have a wetsuit can do this by hiding in a remote corner of the map. The reason it isn't suggested however is if a villager wanders up near you that'll reset their counter, they can't do that if you are far enough into the ocean.