Vados: Do you know why Hit’s attack is called Time-Skip?
Champa: Because he stops time, right?
Vados: He’s not actually stopping time. To be exact he’s skipping time.
Champa: What’s “skipping time”?
Vados: And Hit can store the time he’s skipped.
Champa: So what is that?
Vados: And with that stored time, he can create a separate space, a parallel world. And he can freely move to and from there. That’s why he can be seen but not touched.
Although that is the correct explanation as it is applicable to the variant of the time-skip he used in episode 72, the explanation that would make sense would be to say this: Hit, by skipping time, creates a pocket time-space continuum where he can stay for as long as the skip is. For a 0.1s time-skip, Hit can stay in that pocket dimension for up to 0.1s but during that interval he can freely move in and out of it in order to attack. Goku tries to predict where Hit will hit next and aims for that point of re-introduction in order to counter.Goku (while fighting Hit): You’re somewhere else when you get attacked aren’t you?!
Hit: Exactly.
Goku: But you can’t attack staying there! That’s why you come back here when attackin’. I aimed for that moment!
Hit: It’s not that I can’t attack. (and proceeds to use one of his assassination moves of what seemed like punching through the dimensional barrier). I can do an attack like this.
Goku: You really are amazin’!
Also it's worth noting that in episode 104, Dyspo was countering the timeskip by quickly attacking Hit before using it. It takes Hit a brief instant to initiate toki-tobashi and Dyspo, being able to detect that moment (by detecting the characteristic frequency), was using his great speed to attack Hit while he was trying to perform the technique's initiation.