I use crc on my cube and it is great. I have not tried vegatable oil and I dont want too. I tried a cube with lubix and it turned great. When you get a guhong then get lubix.
Yes, but Lubix is stilll recommended (atleast by me) and you will love your Guhong when you get it. I had to try about 5 different DIYs before I got to the Guhong and it is my favorite.
One last thing, don't use vegetable oil or any type of cooking oil. This will ruin puzzles... nuff said. So get some silicone lube (i.e. Lubix, CRC, Jigaloo, Shock Oil).
Yes. I used to average around that time for a long time, then I got a Guhong, my times dropped down to around 19-21 seconds, after getting used to the cube, I was sub 20 regularly.