I have used several approaches. The most convenient is to use Kodak TCN 400 and to have it processed by DALE Labs with the slide option (prints and slides). It's also the least expensive option. It cost about $3 extra for the slides.(posted 8455 days ago)I haven't tried the Agfa BW Slide film yet.
I used to use the older style BW reversal processes - with rexposure, using D19 as the initial and the redevelopment developer. It uses the published Direct Positive Bleach and Clearing Bath. It worked well with Panatomic X, and Agfa 25 B&W. It works best with thin emulsion films. Haven't tried it with Tmax 100 yet. It's a tedious process. It requires experimentation. First Development times were about 8 minutes. Panatomic X exposure speed was about 80 ASA.