I would advise that you only do a 'omnidbinit' under very specific circumstances when directed by the Response Center, and, even at that, I would ask why
The reason being, when you do the 'writedb' nothing has changed in the IDB. If something comes up, like having to do a quick Restore, you can do it right away. 'omnidbinit' is, just as the command implies, going to totally wipe out the IDB
Only if the structure of the IDB is totally destroyed would I recommend doing a 'omnidbinit' between the 'writedb' and 'readdb', and, if that was the case, I would probably bring in a copy of the Empty IDB from the NewConfig directory to totally start fresh
Always, stop DP, and make a copy of 'db40', or have it backed up on tape before doing the 'writedb/readdb'