Honestly, Tengas are really expensive, but I hear they are a great buy for the long run. My SO has a Tenga and its really easy to wash out. Whereas a fleshlight is harder to do so with. You also will not get the same realism with a Tenga that you will with a Fleshlight, but more choice as far as texture goes. Tengas are also a lot more bulky than a Fleshlight, I was surprised to see the size of the darn thing.

That's just my two cents.

Well, it may be good to clarify WHICH Tenga.

The Tenga Disposables I've used more than once by cleaning them out carefully. I REALLY Like the Deep Throat Cups.

The Tenga Deep Throat cup has a soft foam lube ring that can be removed, rinsed, re-loaded with lube, and re-inserted. The tricky part is washing the inside texture. The sleeve is glued in place at the bottom of the plastic cup and is NOT removable. There are vent holes sliced into the bottom of the insert to allow air movement while thrusting.

Getting it rinsed and washed properly is difficult, and can cause mold/bacteria buildup if not washed properly; Hence the disposable part.
I've used mine several times, and wash it with a water/soap combo followed by alchohol rinse just to keep bacteria at bay. No issues for me yet, but again...it's cumbersome.

The more expensive Tenga flip I do not own.

I purchased two fleshlights and am considering a third because they last. They are easy to clean (See my video), fun to use, and have different textures which don't get boring as the intensity changes with different positions of use.