There is a specially-formulated spray paint for plastic/resin products. It's right next to the other spray paints at most stores.

I had this same problem a couple of weeks ago on a dining table we received from a relative. The top was partially discolored (it looked like the original protective covering had been partially worn away). I was hesitant about sanding it but I was refinishing a couple of smaller tables at the same time, so I figured what the heck. I got some fine grit sandpaper and lightly started sanding a small section, just to see what would happen. The old finish came off pretty easily and it was kind of gummy little balls (I had to change paper often). I went ahead and sanded the whole surface and then applied a polyurethane clear coat (3 coats). The table looks really good now. I think as long as there is no stain in your table, you should be able to sand it down no problem.

that's a fairly large size (30 in diameter will be about 45 gallons). shipping will be expensive you could go to local nurseries and see if they have extra or used 45g containers. a local specialty fertilizer store sells them for $45 (new) here, but a nursery said they would sell me a used one for $10. theyre not not super pretty but definitely hold the amount of soil I need

How about something like Goo Gone? You might have to use soapy water afterward, as it tends to be oily, but I love it for everything “sticky!” Good luck!