Go to a store and remove all the money from your wallet or purse. Hand it all to the salesperson – all of it – and say, “Give me this much worth.”
Gesture ambivalently at their entire stock. Then turn and meditate while your items are gathered randomly by the puzzled clerk. As you hand the salesperson your money, pay close attention to the look of it, the pstench of the auras that have accumulated on it, the feel of the pretty pieces of paper as they slip from your hands. Feel the lifeforce of the salesperson through the currency.
Then, in that gap of time as the money leaves you, as you pass through that moment of going from the material world to the world in which you have nothing, in that moment, sense the Slack.
DO NOT LOOK FOR IT, or you will miss the moment. In that brief period between having something and having nothing, there was Slack.
When you had something, you were responsible for it; you had to do something with it; spend it, save it, invest it. When you had nothing, you needed something. In both states you had desires.
But in that interval between having and needing, THERE WAS SLACK. GO INTO THAT MOMENT. GAZE.