Yes, and I actually had a lot of success this way. I read many threads on rollitup before my first time cloning. I bought a cloning tray and cover, a heater and some rockwool. I should have bought the thermometer too as most clones did not make it. But I do have a few of those clones flowering right now. My friend told me of the technique his mother uses. She learned this gardening old-school style in Poland and continues to clone flowers this way. I bought clear plastic cups. I took my clones like normal. I did use cloning gel though the Polish method does not require it. Not using gel makes cloning take longer. Just take your clones and leave them in the plastic cup with your water. My friend's mom uses tap water though I opted for Reverse Osmosis H20. It worked faster than the cloning tray with rockwool and had a higher success rate. Next time I'm using the rest of my plastic cups. Total cost of the tray/rockwool/thermometer/gel was easily $100. Total cost for the Polish method was $5.