fetch them with flymode and take them 2 some room with no exits- but then the only way out is 2 kill urself or pick them up again but still...
1.Make a exitless room
2. Make the floor have the event: SetasCheckpoint
3. Spawn a telespawn
4. Name the spawn "Tele1"
5. Spawn another telespawn Directly outside the room, or in the main map spawn area.
6. Name this "Tele2"
7. Type "/Tele1 (playername)" To jail
8. Type "/Tele2 (playername)" To free.