It’s quite an old idea, not mine, you can google it or go here, here or here to see how other people doing it. Below my variation of same old trick. The biggest benefit IMHO is that the moisture is not building up inside air bed, and obviously is super quick. You can still splash £30 on Thermarest NeoAir Mini Pump if you like, but that’s couple bottles of wine or new Schwalbe Marathon (plus beer for fitting procedure), or 6 bags of coffee… all above better than another unnecessary gizmo.
I cut threaded part of bottleneck from PET bottle and make hole in the cap
from piece of plastic (ice cream box or sth) a circle has been cut same diameter as bottle neck with hole inside, which makes kinda washer
3 inch piece of road (18-25c) inner tube for nozzle
inserted plastic “washer” into inner tube
everything put back together
I made a hole in plastic bag and put nozzle through
to seal the connection, wrapped a piece of velcro ( might be a rubber band or something)
alternatively the bag can be trapped underneath cap, just screw the bottleneck in
now you can “grab” some air with the bag and squeeze it into sleeping mat. Once technique is mastered should be a bliss. On the picture is Big Agnes Air Core and took about a minute to inflate it. Basically 3 bags of air squeezed in, job done. The small rubber o-ring I added for extra grip on the valve.