Choose between denoise filters and set parameter values

[Nemesis]

I started using Avidemux 2.7 last summer.

I know one size does not fit all, but I would like to hear some suggestions regarding the use of denoise filters, especially fluxsmooth and hqdn3d.
Which one do you use and why?
In another topic fellow forum member xtro suggested using hqdn3d with conservative parameter values of 2:1:3:3
For at least a couple of my videos, I found xtro's suggestions produced better results than default values of 4:3:6:4.5

Any suggestions regarding fluxsmooth parameter values?
How do you choose between fluxsmooth and hqdn3d?
Which one would you use on a video from a streaming site (copy of old vhs)?
Please try not to be very technical, because I have some but not a lot of experience with Avidemux.

Thank you in advance for your help.