I have used a small oil funnel like this https://www.amazon.com/U-BCOO-Multi-fFunctional-Extension-Motorcycles-Gasoline(2/dp/B07PMNLMYR/ref=mp_s_a_1_3?crid=WW5JU1DM63OF&keywords=small+funnel+flexible&qid=1653323671&sprefix=small+funnel+flexable+%2Caps%2C194&sr=8-3 And a bottle of water, after shooting at the range to throughly wash out the bore/ chamber without getting anything else wet.
water ring/halo - https://www.amazon.com/gp/product/B0055F55O6
Gives me evenly distributed watering without having to move the plants or break my back.