No you both need Fastpasses to get in to kidswap. You need to bring your kid(s) thru the line with both of you and then the 2nd rider waits for the 1st rider by the exit - again you both need to walk thru the line or wait first though. Also, you can get FASTPASSES with your kids ticket passes too so that will save time as well. If you have 2 kids, that is 2 adult rides you can FASTPASS at the same time. Remember though - only one FASTPASS at a time per ticket.
What works best for us is doing single rider lanes for Test Track and Mission Space and anything else that has it. That way - you don't have to drag the kids in line. I never have waited anymore then 15min in singles lane so FASTPASS isn't worth it for any of them - save it for Soarin! In Mission Space there is a playland sorta like what you would see at a McDonald's for younger kids and a virtual arcade thing for older kids so take turns with them there while you do Mission Space single lane. We then do Test Track and get a mickey bar or something to relax dd while we switch back.
For MK, we usually do one day where we go to Splash and Thunder first thing (obviously NOT the first day) but when we go back for a 2nd time. We keep dd busy with the water that sprays out of Splash Mountain and then usually go the Aladdin's carpets right after that. We don't usually do Space Mountain anymore but if we did, we would do the people mover (dd loves that) while someone went in.
For MGM - we will do FASTPASS for ToT and RnRC together using kids cards too. We then come back during that timeframe and just keep the kids out front entertained with a (yes you guess it) Mickey bar or even take turns with Beauty in the Beast if a show is running.
So far there is nothing in AK that dd doesn't do with us.
HTH some!!
Suzanne