Yeah, stopping the crons would be your best bet.  Right now there's no built in pause button per se, but sometimes when I want to keep some of my money available when it comes off loan, I'll use a High Hold set to a really high interest rate.  That way if something crazy happens and interest spikes to 1% or something the money will still go out, but in all likelihood it will be there waiting for me when I need it.

I have been asked for a pause feature a couple of times now though, so I may roll that into the next update.  I would be pretty easy to add.