I've been enjoying the shorter general warnings at the top of the podcasts lately, especially the variety, as in #417:
Dr. Harcourt shivered. So, what you're saying is this is a horror podcast. My God! There could be adult language and situations inside!
They're like super-short stories to get the listener into the horror mood as the podcast begins. I love the tone. If you can keep up the varying openers, great; if they're too time-consuming, though, that's understandable. In general, I think they work fine as general warnings.