How can I remove arrows stuck in a player?

I think the easiest way around this is by having gamerules doKeepInventory and doImmediateRespawn set to true, and then a command block set your spawn where you are standing ex:

/execute at @p run spawnpoint @p ~ ~ ~

then another with

/kill @p 

This should kill you, thus removing the arrows, but have no actual downsides. Not sure if the writing for these commands are 100% accurate. I don't have them memorized

-replace @p with your minecraft username or any selector

it disappears after a while. you can die on purpose somehow and respawn, and the arrows will disappear when you will have respawned.

In 1.14+, if a player gets shot with an arrow that has PierceLevel:1b tag, the arrow won't be in the player model. Maybe that could help.