You're right about leaving the leaves on till they are yellow and absorbed back into the bulb. Please don't throw it onto the compost heap. I take the dead leaves off mine, then put them in a darkened room and water them very sparingly till they decide to put a leaf or a flower bud out after a few months.
Then I put them in new compost, bring them out of the dark and start watering again, then see how the flower stalk shoots up, it's almost an inch per day 
My dad bought me one of those giant amaryllis bulbs over 20 years ago and it's still going strong, she's had many daughters in that time, I've kept some and given lots away, she's my link to my dear dad, no longer here