Do power conditioners help with unwanted hum/noise

I just took a three-prong adapter and cut off the ground portion.  I then took my MIT Power cables and plugged them into the adapter and then into my noisy SR orange duplex outlet.  It went from a buzzing noise to almost dead silent.  I guess based on that test I have a grounding issue.  The next step is to talk to Equitech and get a tech out to the house.  

After 18 months of fighting a hum, I called in an Audio Sound Room electrical engineer to evaluate my whole electrical grid and components.  We spent 4 hours together going over every cable and cord that have and even exchanged DAC's to try and identify the problem.  The only thing that cured the hum is when we used a cheater plug.  After talking to fellow audiophiles on WBF, a person suggested I try EbTech Hum X.  For $80 I said what the hell.  I plugged it into my more prominent hum amp and the hum was 99.5% gone.  I ordered another one and sued it for the other amp.  Dead silence.  So, for roughly $160 I cured my hum problem that I have been fighting for over a year.  

I have an all-tube system and have had a slight hum for about a year.  If I plug the amps directly into the SR orange Duplex outlet boxes the hum is louder.  If I plug the amps direct to my InaKustic 3500P PC the hum is there but not as prevalent.  It does not affect my sound quality but it is annoying because I know that it is there.  BTW, I have a dedicated 20amp line.  My next step is to plug a 2 prong adapter (no ground) into my MIT power cables to see if that changes anything.  

Thoughts?