Splited Glissando How to Notate it

Oh! That's funny since loco can also be a cancellation of 8va. Loco as a playing description should probably go above the staff, but I'd consider using a different word if you have it near the 8va!

I've never heard of "loco" being used as a playing description either. The way I used it was meant to explicitly cancel the transposition -after- the glissando part.

"Loco" stands for "in place" and, as mentioned, usually means the cancelation of 8va parts - but also other forms of transpositions (although it clearly appears most often after an 8va/15ma/8vb). Using it right below an octava will definitely be confusing.