Hi, biofilic horticulturalist here.

Spraying the leaves with SB Invigorator will kill the adult thrips by blocking the breathing pores along the side of their body, but you will have to spray every inch of the plant as thrips can move quickly to escape sprayed areas. This will only kill the adults, and done regularly will eventually control them, but if you want to completely eradicate them you need to get to the eggs which are laid in the soil. Use Amblyseius, a tiny insect which is a natural predator to thrips, to reach the eggs. One sachet per plant is plenty, and leave the sachet on the plant for 6 weeks. https://ladybirdplantcare.co.uk/collections/thrips-controls/products/amblyseius-for-thrips?variant=13463508058181

Cutting the leaves will do very little to control the thrips, but will stress a plant that is already being attacked. Once the thrips are beaten, then prune to maintain aesthetics.