I know no one that recommends it. I did it because I believe these things depend on each other for survival. I did reduce the dose on each by 1/3 so I didn't completely destroy my liver. They actually seem to work better in combination. I've taken Prazi, Iver, Fenbendazole, and valbazen all the same time for short periods. The only one that gives me a bad reaction is the Valbazen. Bad Herx though.
There is NO instant kill. You'll have to take these meds for a very long time so you need to work out for yourself at what dose you are comfortable.
The strongoloids are on a 14 day cycle so once you figure out when that is you can focus on them at the peak. I use Iver and doxycycline every day for strongoloids (not recommended) At every 14 day hatching I add fenbendazole. At my worst I took prazi at the mid point between strongoloid hatching for 4 days to kill tapes.
You really have to do some trial and error to determine what works for you. Get Mattk3's paper on his experience. He has many insights that may be helpful.
I know of NO interaction of the drugs. I mean...we are led to believe that the drugs will react with each other. I don't think this is true. The only reason it is not recommended that they be taken together is because they over load the body. Caution in dosage size should avert this.