I just happened to be reading that one message that Dennis posted about Dad's tape when it occured to me to ask that question. But now I know that there're are different threads for different topics. Someone was nice enough to explain to me what 'slack' was. Now I can tell you that nothing I said really applies to your question. Slack can be money.
Slack can be sex.
Slack can often be nothing more than an attitude. What Slack is is appreciable by knowing when you DON'T have it. Slack is the state of not wanting anything because you already have it. If you have Slack, you won't be poor, or have horrible luck. Or kill me.