The easy rule is,
L$-in, L$-out is not allowed.
Sorry Lewis, but I can think of numerous examples where your simplified rule will give wrong results.
As I have argued in previous posts the TOS only applies to wagering, which can be defined as "To risk or stake (an amount or a possession) on an uncertain outcome." I suggest that a more correct simplified rule about the TOS is this:
"no wager no problem"
So, a no-loose sploder is ok, even though there is "L$-in, L$-out". My answer to Cyllya's list: Ok are Contestboards, No-loose sploders, Free-to-enter raffles, Word scramblers, and Trivia balls. Not ok are Loose sploders and Pay-for-ticket raffles.