Dettol liquid soap’s refill packs (above) have a small flaw in their cap seal rings. The tiny ring that stays on the refill pack (after breaking off from the cap), is not secured in place, and tends to fall into the soap dispenser.
Lifebuoy liquid soap refills (above) on the other hand, seemed to have designed the spout in such a manner that it arrests movement of the seal ring once broken.
A small design element, but saves you from having seal rings in your soap dispenser. =)