Yes B., I have been exactly where you are right now.
The first time, my daughter was about 2 and my parents were gone, so it was only me and her at home. They came home and my mother was absolutely furious to find that the baby was stark naked as the day she was born. I told her that I had been fighting with my daughter all day to keep clothes on and NOTHING was working but she was more than welcome to dress her all day long if that was what amused her. She proceeded to dress EV and EV proceeded to strip for my mother. They did this for about 2 hours. EV won.
Now for the peeing every where, I would recommend beginning potty training. Don't get frustrated if he has trouble. See if Daddy or one of the uncles can help with this. Since we don't have the same plumbing as boys they seem to learn easier by watching older guys.
About the staying clothed - you can fight all you want but if he really wants to be naked guess who's gonnan win??? I let it be as long as were at home. We made the deal that when we had to go out in public or when we had company she had to stay dressed. I explained that it was only nice and she agreed so we had no problems with this arrangement.
Now for the bad news - EV didn't stop running around the house naked until she was about 9 - when she started becoming a young lady physically. She would check with me to be sure that it was only me, her, and her little brother at home and then she would strip. When men came home, she ran off and got dressed no problems. My husband actually had to call me from the driveway to see if he could come in the house or if he had to wait for her to go to her room.
My advice - I wouldn't fight with him. If he really wants to be naked, let it be. It hurts nothing (except the upholstry and the carpet till he is potty trained.)
Take heart - at least it's only at home - he is not doing this at other people's houses or in public (like the grocery store or church).