Should I use fixatives for pastel drawings and which works best?

One of the dilemmas of pastel paintings is that they're very dusty and smudge very easily. You would think that the solution is simple

Sennelier Fixative Sprays

Using Fixatives - Grumbacher Art

Oil Pastels Beginners Guide

Winsor & Newton Artists' Aerosols Workable Fixative, Transparent – 400ML, 1 Count (Pack of 1),Charcoal

Perfix Colourless Pastel Fixative

SpectraFix Fixative Is The Natural Choice!Degas SpectraFix Non-toxic Fixative contains casein, water, and alcohol. The formula is an update on a

Spectrafix Degas Pastel Fixatives

Easy Tips On How To Protect Pencil Drawings Without Fixative

Mixed media painting using acrylics and oil pastels – how I combine the two – Katie Jeanne Wood

3 Simple Ways to Stop Oil Pastel from Smudging - wikiHow

Use Fixative? Perhaps. Felicity House's Take On The Subject