Is it easy or hard to dye clothes with RIT dye? Is it worth it?

It is very easy but the end result totally depends on the fabric you are dying. Cotton, rayon and linen take dye pretty well, although linen will fade with washing. Synthetic fabrics, like polyester, do not take dye very well. So if your fabric is a cotton/poly blend, it will hold the dye according to the percentage of cotton. Very often even cotton clothes are sewn with poly thread, so don't be surprised if the stitching retains its original color. Since your water for using RIT must be very hot, you should consider whether the fabric will shrink. There is a cold dye called Dylon as well. Once you've taken all of that into account and decided to dye something, I have a few tips. Make sure you do it in a large enough tub for the fabric to move freely. I often use those big plastic storage tubs. Use really hot water, add a cup of salt and stir it constantly so that the cloth does not end up darker in spots and lighter in others, unless that's what you want. Also, the dye will stain bathtubs, washing machines, and your skin and it can cause skin irritation too, so don't just stick your hands in it. Hope it works out for you! Good luck.