Keg carbing right or wrong

There is no one way to brew there are many ways. Just comes down to what works for you.
Today I kegged my first batch (20 gal). I've researched and read for awhile. And pretty much most people prefer the set it and forget method or a form of. But today I was to hook up to the liquid side, set it at 30 pounds. Purge the oxygen out. Then for a few minutes or untill the bubbling stops shake or tap the keg to get gas to dissolve in then let it sit for a couple of days. Is there any good reason to do it this way or is it even a way to carb.

Let me clarify. I was told to do it this way. I didn't even think about it until I heard more about this method.

Well personally I find its always a good idea to let the keg sit carbing for a week or so. For some reason it tastes better. However I either put sugar in the keg or do set it and forget it for the week. (12psi or so). Also its always a good idea to chill it for a day or so before dispensing. Again, just tastes better imho.

When I have in the past tried to accelerate the process, even on beer which has been in the primary for 4 weeks, it doesnt taste mature after only 2 or 3 days carbing. It may be carbed at that time, but i find not mature enough to really enjoy. I actually think it tastes the best 2+ weeks in the keg under carbonation. The longer the better, but the most i have ever been able to save a keg without cracking it was 4 weeks.

Using the process you describe it's very easy to overcarb the beer.

I agree that the extra time for the set and forget method is beneficial for most beers. If you're really in a hurry, I'd suggest either a higher pressure or shaking, but not both at the same time. A lot of people have good luck with setting the pressure at 30 psi for ~36hrs and then purging and setting back to serving pressure. Another option is buying a carbonation stone. Using a stone you can fully carb a keg in under 24hrs without any risk of overcarbonation.

When I first started kegging my SOP was to set it and forget it somewhere around 10-11psi. The beer would be ok to drink after 7 days, but I noticed it was perfect after about 2 weeks. Then I'd dial it back to 5-8psi. I got tired of waiting so long (only have a 2 tap system) so now I do it different, quicker, but with good results. I seal the keg with the gas up to 30psi. It sits for 24hrs at 30, then I dial it back to 15psi and it sits another 24hrs. Then down to 10psi. At that point it's good enough to drink, but will be perfect within the next few days, obviously depending on the carbonation needed with the style of beer. When it reaches the desired level (usually within 4-7days) I dial the pressure down to 5-10psi for regular dispensing. Again, depending on style. This has worked well for me over the last 6 months or so.

Hope this helps!