Phil,

I did my valve cover leak job back in 2016 - my engine has NOT A DROP of seepage to this day. I didn't use ANY locktite or other product.

But what I DID do, is take my time and do the job right. I followed Max's advice and invested, probably, six hours in the repair. I spread my time over two weekends (mostly cause I was traveling during the week and let things sit all week to set up).
In my case, I took the breathers/valve covers off as assemblies and separated them once they were off the car. All four parts got cleaned inside and out with gasoline to remove all RTV and oil. I then used "Simple Orange" or some other product and cleaned them to the point you could eat off them.

I then let all parts sit overnight in front of a dehumidifier. I then applied my RTV as per Max's advice and bolted the breathers to the valve covers, finger tight. After 1/2 hour, I tightened the bolts to 5 footpounds and let them sit in front of a dehumidifier all week while I went to work.

Following weekend, I put the assemblies on the car with new valve gaskets and tightened bolts to 7 foot pounds (these torqes are what I remember, just look in the service manual to confirm these numbers).

And yes, I used NEW bolts from NEEDSWINGS. Again, no leaks in 20,000 miles and four years. Take your time, do it right. DO NOT over do it on the RTV, do what Max said, fill the valley of the breather and press them onto the valve cover - putting too much on means the breather cannot sit properly on the valve cover.