try it for yourself
open a disposable whonix-ws
type in forum.qubes-os.org
press [ctrl]+tab
type in guerrilla mail
From now on, work parallel, while you browse the forum, click on the first link in duckduckgo, which is https://www.guerrillamail.com/
guerrillamail automagically gives a random account, in this case xpmjoveh @sharklasers.com
then create new account on this forum
copy/paste email
as username and name I just select the text before the @ and press middle-mouse-button twice
as password fill in whatever
then wait for an email to arrive. But you don’t have to wait as in the meantime you can do other stuff, like open a mousepad and start writing your forum-post 
When email arrives, click a link, and another link.
Is this cumbersome? Sure. But if you use the same account with a decent password, like one generated by < /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c${1:-32};echo; for example, then I’m not even going to try to remember that… so in that case I have to boot [vault] to open my logins/passwords file, then [shift]copy/[shift]paste it, which is almost equall cumbersome…
Maybe there’s a better/automated way to manage passwords cross-qubes, but I haven’t looked into that yet :-/
Or use a simple, easy to remember password that is easily compromised… but then what is the point of having an account if it’s not secure? (or - God forbid - use the same password as you use on other websites)
dunno, that’s a personal question. To me it’s like second nature…, so to me it is.
I would encourage everyone to use the same method as that would increase both your and my anonymity :-p
The down side is of course that we can’t build up a reputation, but I’m not ruled by my ego, so that’s fine.
Also, anyone who knows the email address you used can easily change your post using “I forgot my password”. (Have fun changing this post :-p )