Water damage is the kind of thing that if you need to ask, you can’t do it, especially with iPhone X/Xs. Soldered duel layer board makes it easy to absorb water, and extremely difficult to open up, clean and repair.
Also rice does not help anyway Even if it does, it is recommended to open up the phone first to let air circulate. Water resistant iPhones are sealed pretty tight even though there is a leak that caused water damage in the first place. You need to at least open up the SIM trey before attempting to dry it out. Now water is inside it for several days, your only hope is sending it to an expert.