SCT Controller described a probable MMTJ airspace infraction during an attempt to demonstrate to a developmental vectoring techniques to avoid parachute drops near SDM; the reporter acknowledges the jump activity should have been delayed.

Narrative

I was providing OJT on the SDZR position. There was a lot of parachute activity at the Trident jump zone 2 miles east of SDM field. There were also a lot of IFR arrivals coming out of Mexico landing at SDM field to clear customs. I attempted to demonstrate to my developmental; differing techniques of vectoring the arriving aircraft around the jump zone for a base leg entry over the prison; which has worked successfully in the past. Aircraft X did not descend as expected and was making an unexpected 360 degree turn to get down. I noticed that the pilot was turning toward the jump zone and jumpers were in the air. I instructed the pilot to make a turn to the right to avoid the jump zone; which was successful; but this instruction was going to require coordination with MMTJ Approach; as the aircraft's rate of turn was going to put it over MMTJ airport; only 1.5 miles south of SDM field. Due to traffic volume and complexity; I was not able to effect the coordination before the aircraft was overflying MMTJ airport. I believe the Supervisor or another Controller effected the coordination in time; but I am not certain of that. Recommendation; I should have delayed the jump aircraft and not attempted to show my developmental a more expeditious way to handle the arrivals into SDM field. I mistakenly assumed that the pilot was familiar with making a base turn over the prison; which has worked successfully in the past.