I have a blood clotting issue, ITP. Nothing lethal (yet) but quite a nuisance when you cut yourself while shaving that 1 time a year. Alum doesn't work for me aswell as it's supposed to. An ice cold rinse works better. And now I got this Proraso gel.
When I cut myself it is always in the lower neck region and consequently I mess up my shirt collar. You just wipe off the top of the tube and apply your wet finger to the affected area, let it dry for a few seconds and you're good to go. The gel does not sting like alum.
When it dries and your turn your head, it feels a little like an invisible patch on your skin. Whether it's a true astringent I'm not sure. Maybe it has its roots in the construction sector for waterproofing roofs but hey, it does the job. No messed yup collars for me anymore!