Most gliding clubs in the UK face this problem every spring, with pilots who have not flown since the previous summer. Nothing new in that. All the clubs I have been in have had a core of instructors, I was one, who flew all the year round teaching people to fly in winter ready for the next spring. I remained 'current' throughout the whole of a long career in gliding. In spite of what you might think, you can soar in every month of the year in the UK, as my log book will attest. As for rustiness - yes it does exist, but for a well trained pilot it should be dealt with by a few duals. My own experience of this was when, after a 28 year layoff, I decided to see if flying was like roller skating, something you never forget. I booked a week at my local club, had three duals, and was sent solo. But then gliding is a 'hands on' kind of flying, Airline flying these days seems to need so little time actually hands on. Maybe that needs to be addressed..