Depending on prop design and pitch, engine-idling can either stretch a glide or shorten it, compared to ignition-off. It's worth exploring both flight regimes in your particular gyro.
Like Anthom, I will sometimes slow up intentionally to lose altitude when I'm too high. Once you slow to, say, 10 mph below your best glide speed, your flight path will steepen noticeably. Be gentle with your back stick -- this is not to be a mid-air landing flare.
You must have a sense of when to speed up again. This recovery must take place at least a hundred, and probably more like two hundred, feet off the deck -- you will initially drop like a stone when you apply forward stick pressure to speed up.
I perform final approaches at idle whenever possible. It's good practice. This is not, however, safe or even possible at all airports. Fixed-wing traffic catching up to you from behind on "ten mile final" will not be looking UP and may not see you on your 45 mph steep approach.