I would be really cautious of running water on slippies as a habit you guys. Most are brass or nickel silver pins and these can oxidize over if you make a habit of it. I'd recommend using a small screwdriver and an old tee shirt rag and push it down in there to clean off the areas exposed by rubbing the rag up on the tang and around the blade using the screwdriver. Close and open the blade and do the other side back and forth just like that. Then move to clean parts of the rag and do it again and repeat with each several openings.
Once you get all of what you see or the rag stops coming up dirty then use something like Tuff Glide dry lube that goes on wet and then dries. This will work down in there and hopefully help to move some of that debris remaining in there that can't be seen out to where you can then again later rub the rag down in there with the screwdriver.
I get a lot of referal work from Kabar knives all the time, several times a week some weeks and I see a lot of the old slippies from other makes also for new pivot pin replacments. When I've inquired about this a high number of them confess to having cleaned their knives using streams, faucets, canteens, jet sprays of water like power washers after field dressing, or even dishwashers. All these but the dishwasher are probably fine once in a while if you spend the time to adequately dry it out but only once in a blue moon. Most don't spend the time to dry them and to be honest you can't really get into the places the water can get to that you can't so that you can dry it out properly. As a result these areas remain wet so I'd not make a habit of doing this unless there is simply no other way to clean it.
I have a 'take apart knife' by BullDog knives and about once a year I'll take it apart to clean it and I don't even carry this one all the time. You can't get to the places inside it without being able to physically access it trust me. Even when I thought I have cleaned this one I realized afterwards that there is usually a lot missed that is left in between the blade and liners. Anyway, enough pedestal talk here. I would just be careful using a lot of water to do what you should be doing with a rag and some lube. I'd be really cautious of sticking an oily knife down in your pocket also. The oil or grease attracts grit and pocket lint and defeats the purpose.
You want to know how I do it? I carry mine dry. When I use lube they don't go back in my pocket until they are dry. I recommend this for you and you should have little trouble with your slippies. Otherwise in 25 years you'll be searching out trying to find someone that can replace a pin for you when you go to cut and it pops apart on you. I have one coming to me from Kansas right now for just this problem.
Thanks for listening.
EDIT: Obviously there are many stainless slippies. If you happen to own one and you know its stainless, Swiss Army Knives, or others of that ilk well, they will endure water better than those I refer to above. My thoughts were of course primarily dealing with the bulk of what I see which is the more traditional bulk majority of nickel silver pins and liners, along with the brass pins and brass liners type folders. I was not specifically thinking of stainless ones. I would say if you prefer this method of care that perhaps a good stainless lined, pinned outdoor folder like the SAK would be a better choice for you though. :thumbup:
STR