What massager should I use?

Sounds like you may be anxious for quick results! When you feel the tingling you just need to relax and let it take control! Relaxing is key as well as rewiring your brain to focus on the prostate. You might also try some gentle nipple play to rev things up! You will eventually find that almost any toy is capable of producing good results! Good luck and enjoy the ride!

@fred27 Thanks for the feedback. I agree relaxing is a big key. This is one of the main reasons I like to use the do nothing approach, it allows me to relax and feel my prostate react, even if it is for a short duration. I like the idea of trying the nipple play. My current plan is to use my eupho more regularly and enjoy the stimulation it provides.

I think the Eupho model that you have is a great massager.  I would try to make a go of it in the following way that works for me to create longer lasting "tingling feelings" as you call it, or even other feelings that last longer than 5 minutes.

I usually plan for ~45 minutes for my session without anything after so I do not rush.  After a shower to get all clean down there,  I take the time to lube my anus slowly and well with two blobs of water based gel type lubricant.  I do this lying down, so that everything is more relaxed.  Then, I put a long bead of the gel across one edge of the shaft of my device (happens to be a Helix Syn V, extremely similar shape to your Eupho) then smear it around the shaft all the way including across the length.  Then I insert slowly into the anus opening.  I actually do this in front of a mirror so I do not miss. It almost gets sucked in after a short start, first exciting me with something touching up there against the prostate.

Then I start some Kegels, 5 second ones with deep belly breathing, about ten (10) of them.  Because I am in front of the mirror lying down, I can see my penis move: that is the signal that I am doing these right - very important.  I will include a link for details on proper Kegels here to save having to write it all out for you:  https://www.youtube.com/watch?v=MJ7EfGu03-0

By this time I am starting to secrete pre-cum and I just let it flow unless it gets too much, then I wipe away.  I try other positions than just on my back, like the side, or on my knees/on all 4s.  I do not stand up yet, just relax the legs.  When I am on my knees, I may do some more Kegels this way looking back through my legs.  The penis is more pronounced/hanging and it is easier to see it bob up and down with each Kegel as you contract its muscle.

Additionally, to relax a little a good diversion that I enjoy is reading a bit on my phone:  maybe this forum, etc.  Then repeat some Kegels if you lose the feelings.

I will stop right here because I just wanted to relate what helps me to you!

I like to relax in my recliner after inserting my HSV or Tempo or Vice2. While doing Kegels I draw my Aneros in to the max and let the tabs work their magic while I enjoy the vibes ticking my prostate as the head moves up and down! Pure bliss!