Do you believe in oil additives?

I was recently having lifter/ valve noise at idle. I was already using Mobile 1 15w50. I put a 1/2 bottle of Rislone in the engine and almost immediately notice issues with idle oil oressure below 2 bar. The oil also turned very dark very quickly.

I did a front seal refresh and oil change at which time I added Swebco 502 per recommendation on Rennlist.

Valve / lifter noise at idle is gone, oil pressure at idle is a solid 2 bar!!

I'm with Wally on this one. Time to move to a specialty oil thru a dealer rep. Since I do this job just once a year, I guess that's not too much of a hassle.
Roger recommends Royal Purple, and have others. I will try that since there is a rep nearby where I live.

Not to change the direction of the thread - I used to believe in Marvel Mystery additive as a cleaning additive prior to changing the oil. I just stick with Royal Purple as it includes what it says it includes - most importantly for our cars ZZDP at 1200ppm.
I am also a fan of Swepco as it seems to work and is recommended by Porsche.
Noisy lifter add some Swepco 502 and it goes away.
I am sure other oils work equally as well. Just check what you are using.