Nice tastyshrimp! 👍 Did great with the lofi wavery echo sound!! (I like where you are going with this though.)
(I have no idea what kind of ukulele you have. (Gloss or satin) The nail scratch you mentioned iap, might work with the back of your nail? You might want to try experimenting with fingerpicks too? A plastic one (or whatever material you like), or some thing backwards on a finger so it’s like a nail on whichever scratching finger might be enough to get the sound you want? It would probably have a higher chance of damaging your soundboard faster if you’re concerned though. Just ideas)