Time to try S/H on one Oncidium

[The Orchidist]

This plant has recently started firing out lots of roots and was packed with lots of moss , before i make the move , does every little bit of moss need to be picked out , does the pot need to be closed at bottom and 2 or 3 holes drilled 1 inch from bottom up and should i trim some of these roots ,to avoid a rotting mess of roots , how deep should i place the p bulbs in the leca balls ,
Should i perhaps place the plant under a dome with heat mat underneath to get more roots a growing , i have no kln on hand but do have some worm castings tea ,from what i hear its good for them.

Any suggestions would be appreciated