Give your chain of command a chance to solve the problem.
Many problems must be addressed to the chain of command for resolution anyway.
Be honest and don't provide misleading information.
IGs will discover the truth quickly in most cases and there are penalties for knowingly providing false information.
Keep in mind that IGs can only recommend, not order a resolution.
Only commanders can order; the role of the IG is to advise the commander.
Remember IGs can only resolve a case on the basis of fact.
Your claim that a supervisor has violated the rules doesn't make it fact. A claim must be supported with evidence.
Don't expect instant action on your request...Be patient.
Investigations take time, and IGs tend to have heavy workloads.
Be prepared to take "No" for the answer.
The IG will determine if the issue(s)/allegation(s) are IG appropriate. If not appropriate, then the IG will hand off to the appropriate agency.
To complain without fear of reprisal is the right of any airman, guardian, civilian, or family member seeking IG help. After all, problem solving is one of the IG's primary missions.