A couple of things from your post - don't assume goop coming out at the valve is getting out at the vale - sometimes it can be coming from further away, tracking inside the rim cavity and then escaping.
eg is that a scratch in the tape ( left red circle)
is that a folded lip on your valve rubber ( bottom r red circle)
is that gloop on top r stopping the tyre edges seal?
View attachment 160280
Finally, I never " wash" sealant off - I wipe it with a sacrificial cloth +/- use metho for the final clean. Then get the glasses put and start again...... Everything should be spotless before slipping a tyre back on