How to make a glue gun?

I am planning on making a puzzle platformer, and my gameplay method will be fps, and I will have a weapon that would place a glue on any surface that the ammo would touch (basically I would put glue on the floor). I know that to make stuff stick then I would make it create a joint on anything that has a collision to it, but what I don't know is how to make the glue itself. One possibility is to make the gun spawn many, really small spheres that would have the "joint creation" script on it, but I was wondering if there is any other suggestions. Scripts for my glue or your ideas would be appreciated as well.

In thinking about this for a while I can't think of a good, FAST way to do it that wouldn't require a lot of crazy math.

The "create a sphere for every blob of glue" is pretty much the easiest solution I can think of, but I would recommend not using an actual sphere for the model or your polygon count will quickly shoot through the roof. You may instead want to use no model at all, an invisible rigidbody with a collider in the shape of a sphere, and perhaps a decal for the glue splat.

Or be careful to limit the amount of glue blobs in play at one time, and model a special low-poly blob that has no polygons behind it to stick to surfaces, for performance's sake.

Another tip for not letting the game be overrun with too many glue blobs in one spot would be for each new blob to detect other blobs around it, and if it's too close, it doesn't stick. Then you could get a natural, even coating of the glue without it crowding and causing unnecessary lag.