Hello so there’s this movie I’m looking for the name of here’s the scene I remember detail per detail hopefully I can find it once & for all

I remember seeing it in around 2015 on a website I know it had to have been a horror comedy like a low budget flick the killer goes around getting everyone until only one is standing here it goes

Starts off with a woman getting ready to shower as she takes off her clothes & her black thong/underwear with her butt showing as she’s turning on the water the killer walks in I remember the dude had a mask & a yellow suit sorta like worker type she then sees him & screams but too late he gets her & grabs an orange box that has either baking soda or some sort of shower powder & he pours it down onto her as she’s coughing non stop with her being another victim

This is all I remember if anyone could happen to know anything don’t hesitate please!! Thank you so much