Line Conditioning and possible ground issues?

I've been doing some research across the web about such.  Some older equipment never had provision for 3 prong cabling with ground.  Perhaps in these cases and if one had an issue with some ground loop hum, you used a cheater plug and the world was right again. 

And that most small kitchen appliances for example cannot have 3 prong plugs.

Of course with a Toaster, where not looking to lessen-squelch line noise like with modern day electronics. 

Some older equipment never had provision for 3 prong cabling with ground.  Perhaps in these cases and if one had an issue with some ground loop hum, you used a cheater plug and the world was right again. 

It’s really not the preferred way to deal with a ground loop issue.  IMHO, at best, it is a way to diagnose a ground loop issue.  

Important to know why that ground pin is there.  It’s there to carry voltage from the chasis to ground when there’s an internal short.  This can be 15A to 20A, the full current at the AC input.  

We recently had an a’goner who had a partial short.  The current went from the chassis, through his interconnects to the next piece of equipment and burned it out.  He literally reported feeling a tingling when he touched the chasis.  That was a huge sign something was wrong.   Had he had a full short a fire could have started by having 15A going through the tiny little grounds in the interconnects.  Had he not had the interconnects and been barefoot he could have had an electrocution.  

If you are sure your house wiring is good, and absolutely cannot diagnose your audio any other way, the best solutions are the small hum busters.  They do disconnect the ground, but restore it on a short.  

Other AC issues which can cause hums are DC on the line, as well as a lifted neutral.  The usual way to deal with DC is to find the source.  Turn off every other breaker and device in your house.  Sometimes things like LED power supplies can cause massive amounts of DC.  A neutral which is not actually well bonded to ground at the service entrance can do similar things.  That's why I suggested the inexpensive test plug to start. 

@markd51 

I can personally tell you that the Audience line of power conditioners will not help with DC current issues.

For safety, there should be proper grounding of the household electrical circuitry.   Any structure - or system - without proper electrical grounding is a potential hazard - fire or electrocution.   Only a licensed electrician should deal with household circuitry.

Using a cheater plug for audio equipment is not safe for long term use.  It’s useful only as a temporary diagnostic tool for finding out what’s causing a ’hum’.

For improving SQ, there are "add-on gizmo’s" that plug into properly grounded household circuitry. *    

For audio components, there are two types: ’earth/chassis ground’ & ’signal ground’. In this video, Caelin Gabriel discusses each starting at 19 min 20 sec.  It’s very informative.

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*After experimenting with different grounding approaches for the past 10 years, I discovered that much depends on the design of the grounding gizmo - and the design of the audio component.   Some components benefit and some don’t.   The only way to know is to try.   Generally speaking, my system’s SQ has improved with grounding.

I breezed through some of Caelin's video. 

I gather his gizmo, the Altiera, which he's showcasing will still rely on correct AC.  That this gizmo, and like any-all others such as perhaps the Puritan Groundmaster City, how then can such a unit actually then ground when the origin of electric service is not grounded? 

Again, I gather no cigar, as Caelin explains a ground is there for safety most importantly, and that safety (ground) must originate and be implemented at the service panel, there's no other way, correct?   There's no magic bullet.