HC-110 Replenisher is the "secret" for one of the classic
classic hyper-pushes -- Tri-X at EI 4000; mix Dilution A, but with replenisher instead of developer concentrate, then develop 5 minutes at 75 F.
Personally, I prefer a soup made with HC-110 diluted to Dilution B using Dektol 1+9 in place of all water, then add 4 g/L ascorbic acid and 2 tsp/L washing soda; fifteen minutes with vigorous agitation every 30 seconds yields near-normal contrast at EI 4000-5000, on either TX or TXT (most likely same with 400TX and 320TXP).
Alternately, you could make up some Dilution B and use it replenished; it's much more economical than one-shotting, but consistency is dependent on using the soup frequently and replenishing accurately.