How can I clean phenol extracted RNA?
Phenol absorbs at 230 nm, this is the most likely contamination in your case. You should try to avoid pipetting from the phenol phase, or use a phase lock gel to make this easier. I assume you washed it a few times with pure chloroform after the phenol/chloroform mixture, that should help to get rid of the phenol.

I only precipitate my RNA with 1-1.5 volumes of isopropanol after the chloroform/phenol extraction, that should be sufficient for most uses. Just add the isopropanol, keep it at -20°C for 30 minutes and then centrifugate it at 9000 g for 20 minutes, redissolve the pellet in water.