Several ways to do this, all involve having the terminal end of the spinn halyard having a stopper knot and the spinn terminated to a cleat, etc. ... so it doesnt go overboard or 'up the mast'
1. Chutescoop, but with the scoop's control lines long enough to reach back to the cockpit and 'double blocked' to the rail somewhere 'under' the foretriangle .... but adds a lot of complexity to raising/lowering ..... as does using a Chutescoop/sock.
2. Allowing the spinn with tightened sheet to be completely wind-shadowed by the main (and unfurled jib/genoa ... careful not to jam the spinn in the top swivel of the genoa). "Blow" the spinn halyard and pull in the foot, etc. before the spin fallls into the water and goes under the boat ... called a BIG DROP where you pull in the spinn faster than it can 'fall'. You need the spinn halyard terminal end cleated to the mast.
3. Tighten 'premarked' spinn sheet, tighten tack-line (Aspinn) or spinn pole downhaul and foreguy on SymmSpinn, Unfurl jib/genoa, 'TACK through the eye of the wind, 'blow' lazy guy or lazy sheet, and heave-to with the spinn forced/stuck to the
windward side of main/jib ... release spinn halyard (terminal end cleated to mast) and PEEL/pull the spinn down and into a hatch/turtle, etc. Practice starting in light wind and work your way up in ever stronger winds.
and the ultimate BEST method is:
4. Get a spinnaker
furler.
http://www.bamarusa.com/bamar-rollgen.htm or a competitive spinnaker furler.
Chutescoops or spinnaker socks, etc. IMHO add a lot of unneeded complexity to spinnaker handling. Simply learn/practice to raise lower with a tight (premarked) spinn sheet, the terminal end of the halyard cleated to the mast and with the spinnaker 'shadowed' by the mainsail faster, safer, easier. Of course you have to practice practice practice to get this 'right'.