So, rice isn't the best idea. The dust can get inside the watch as well causing more issues. If you go this route don't just stick the watch head down directly in the rice, just put in in the same sealed container. A proper desiccant would be a better option.
No watch, regardless of water resistance rating, should be taken in the shower. The combination of heat, steam, soaps, and surfactants all contribute to the degradation of the seals and gaskets making the watch more prone to taking on moisture. The same goes for spas and hot tubs as well.
If water gets inside a watch the best course of action is to open it immediately and/or take it to a watchmaker. Rust begins to form extremely fast inside as the movements must be extremely clean and not every part has the benefit of being treated with an oil or grease or whatever protectant. When I say extremely fast I mean it can happen within minutes. I've seen a Panerai fail a wet pressure test and flood inside the watch, by the time the watchmaker got it opened and partially dismantled 15 minutes later some of the steel components of the movement had already formed bright orange rust.
Slight moisture ingress is generally less of a significant concern, but will still cause long term damage if not addressed. 3 weeks is probably pushing things depending on the extent of the moisture. The good news is, the movement in that watch is about $11, so assuming there wasn't damage to the case, dial, hands, etc the watch could be fixed up for not a lot of money. For what it's worth, I don't see any mention of water resistance at all on the website for that watch, unless it's marked on the back of the case I would conclude it's therefore not even splash resistant. The leather strap doesn't help things, those certainly aren't water resistant. A few smacks upside the head might help set things straight. :lol: