A block is basically a mini-panic attack,which leads to all sorts of unpleasant secondary behaviors, so it’s the worst part of stuttering for anyone who blocks! You begin on an exhale to get past the mini-panic attack. As you learn to speak without the panic, the need to add exhales goes way down very quickly. If you do it while making eye contact and everything else comes out “normally”, a listener will not care. In fact, realizing this is the biggest way to reduce blocks. Listeners (who are worth it) will only “care” when we pause oddly, avert eye contact, gasp for air, say odd things forcefully, etc. and they “care” because they are confused and concerned. A bad block absolutely looks like potentially a serious medical event. When im having a bad day with stuttering/blocking, I’m using the longer exhale once every 6 minutes or so.