The short answer is "no". It might have happened occasionally, in an emergency, but it was not something one would have planned for.
Why? Because a shirasaya is made for storage of the blade only, it doesn't need the strength of working mounts. The wrapping on a working sword hilt (both the rayskin wrap if a full wrap is used, and the cord wrap) provides important reinforcement. The ferrule and pommel (fuchi and kashira) also reinforce the handle. The two halves of a shirasaya "handle" are just lightly glued together, and can easily come apart if used in combat. The traditional glue is rice-paste glue (sokui), which is a simple starch glue. Apart from simplicity and availability, rice glue is strong enough for the purpose, and also weak enough so that the shirasaya can easily be split for cleaning (followed by re-gluing) without damage to the wood. It isn't strong enough to be depended on as the only thing holding the hilt together - reinforcement (wrap, metal fittings) is necessary for hilts made for fighting.
A shirasaya scabbard is also unreinforced. Working scabbards typically have reinforcements at the mouth and the tip. This isn't necessary for combat as such, but for safer carry of the sword - it would be inconvenient and unsafe if your scabbard split into two.
Typical mounts: https://commons.wikimedia.org/wiki/File:Daisho_katana_and_wakizashi_koshirae_2.jpg
Shirasaya: https://commons.wikimedia.org/wiki/File:Daisho_set_of_shirasaya.jpg
Sometimes, one sees hilts that have no wrapping. These still have the fuchi and kashira, and often an additional metal reinforcing band in the middle of the hilt. These are not shirasaya.
An example: https://i.pinimg.com/564x/6d/5f/b1/6d5fb1b141c6ec4e7ceff3f70c712e41.jpg
A hilt with a similar central metal reinforcement, but also with a rayskin wrap (but no cord wrap): https://i.pinimg.com/564x/1e/27/a9/1e27a9ec16c06f6cae0839b02ba69a1a.jpg
There are also mountings without a guard (tsuba): https://commons.wikimedia.org/wiki/File:Aikuchi-J_06006-IMG_0911-white.jpg These are also not shirasaya.
The closest to shirasaya that would have been intended for use in combat would be sword-cane mounts (shikomizue): https://commons.wikimedia.org/wiki/File:Shikomizue_koshirae.jpg These sacrifice strength of the hilt for concealment (or at least, for plausible deniability).
