Use a funnel.

I personally have never had this problem on my SoftSoap refills. The big bottles have a small squirt port in the cap, so I remove the pump in the small bottles, place the squirt hole directly onto the opening of the pump bottle, and refill.

Use a funnel.

I personally have never had this problem on my SoftSoap refills. The big bottles have a small squirt port in the cap, so I remove the pump in the small bottles, place the squirt hole directly onto the opening of the pump bottle, and refill.

Edit: Upon re-reading your question, I realize you are asking for a way to use the actual large bottle instead of the little bottle. I think this would be the last option. Refilling should be easy; I just refilled mine this past weekend and it took all of two minutes. I have had great success with SoftSoap bottles and the Kroger competitor; I can't speak for other off brands