I have succeeded only 3 times in a WILD without WBTB, all I can say is:
1- It’s very nice to achieve, but;
2- You need much much much patience, it takes more than 2 hours to get into most vivid dream stage…
3- You can use a timer with low volume to remind you to keep focus.
It’s very hard, but worth trying!
The sensations felt during you are sleeping are impressive, some very good while others, I admit, some are not.