I love William Castle films. I never really paid attention to him until John Waters wrote an essay about him about 20 years ago in one of his books. Most of his films are pretty stupid, but they seem to hold my interest better than say, the Roger Corman films.
The gimmicks were all fun too like the Punishment Poll in "Mr. Sardonicus", and the Ghost Viewer in "13 Ghosts" and the vibrating seats in "The Tingler".
Even without the gimmicks, Castle films are great fun like "House on Haunted Hill" or even Castle's later "straight" films like "Rosemary's Baby" or "Bug".
I haven't seen "Homicidal" or "Strait Jacket" or "I Saw What You Did" (or if I did, I saw them a looooonnnnngggg time ago, so I don't remember what happens.), but I plan to eventually.
The majority of Castle's films are available on DVD, but not easily, so you probably have to order off of Amazon.