Please calm down. You asked how to use utaugrowl and I've already given you the instructions on how to do so.
utaugrowl has a subtle effect even when the w flag is set to 100. As a reference, here is some audio with no flags, with w50, and with w100:
https://clyp.it/y5afmjll
Here are some alternative methods on how to create a growl-type vocal.
Use moresampler. The flag MG controls growl, which ranges from 0 to 100. Here's a sample using no flags, MG50, and MG100:
https://clyp.it/njijdksu
Use extreme vibrato settings. This technique has the added advantage of working with any resampler, and on both Mac and Windows.
Right click on a note and open the Pitch settings. Set Length to 100, Depth to 200, In and Out both to 0, and finally type in "18" in Cycle. Do not click on anything else in the window. As soon as you've typed 18, press the Enter key on your keyboard to save the pitch settings.
This is what it sounds like without vibrato and with these vibrato settings:
https://clyp.it/xmznc1vv