I use an IR blocking filter.. it mainly tries to keep the dust out, but on this job it fails terribly.
The IR filter really depends on the object - to my knowledge, it makes the most difference on Mars and the moon. On Jupiter/Saturn, it may not make as much difference.
I think the main purpose is to stop the different wavelengths of light leaking into each others channels, as the IR can have that effect. I'm not sure on the scientific reason.. i'll do some tests next time out.