One of the things I love the very most about nylon whips is that we can toss most of those rules out the window. Except the swinging on it one. I only recommend doing that if your life depends on it. I tie those fall knots pretty tight.... It may hold you but it will damage the end of your whip. Then all you will have a an expensive paper weight on your hands.
Feel free to crack it on wet grass or even in a rain storm. I live in the desert and have no problems cracking it in the sand. If your whip gets dirty or grass stained just use a soft brush and a little tiny bit of dish soap (not dawn) to clean it. When cleaning your whip make sure to use COLD water so you do accidentally melt out the wax.
One thing to remember about your HolyOak nylon whip is that it has been dipped in a mixture of paraffin and bees wax. When you first get it, the excess may flake of a bit and that is totally normal and will go away quickly. Just wipe it down with a towel after you have given it a few cracks to encourage all the wax to come off. Most of the whips don't flake but a few of them will. That depends mostly on the temperature of the air on the day that I waxed it. Because of the wax, you don't want to store your whip in a hot area like the back seat of your car or over a heater vent. That wax will melt out and most likely ruin your seat or carpet! Some people like their whip rewaxed from time to time and I am more than happy to do that for you or walk you through the steps to do it yourself.
Don't store you whip where it will be in the sun. Over time the sun can fade the colors.
Cracking your nylon whip on asphalt, concrete and (if you live in Moab) slick rock is not the best choice because of how abrasive it can be. If you do crack on those surfaces, try to keep your movements on a higher plane so your whip doesn't drag so much. After you are done working on an abrasive surface, I recommend thoroughly checking your whip for wear. If you see little fuzz on your whip in places lightly go over it with a lighter to burn them off. Don't hold the heat in on place too long or that will melt you paracord. The end of the fall will also need re-melted from time to time depending on how you use your whip. That is as simple as melting the tip with a lighter and pinching it with your fingers or between two flat surfaces. (take care not to burn yourself!)
Smooth surfaces like the floor in a gym or dance studio are perfect and will not hurt your whip.
When not in use, keep you whip loosely coiled in the natural position. My whips have two curves in the thong. One way the curve is really big and that is called the aligned position. When holding it the other way the curve of the thong is smaller called the natural position.
The most important thing to remember is your whip is made to be played with a lot. So, use your whip as much as you can and have so much fun! Remember to use your safety gear so the fun doesn't have to end.