Ok, not saying it's the only way, you can simply incorporate bombs in your method.
Us the GS "titarnia" with Dragon element, don your best armor without dragon weakness and bring as many large bombs as you can, then material to make the rest. At the start of each area, place the bombs close to the center and wait for Lao to stick it's head in. ignite the bombs when it's within range and continue to rap on it's head with your stick.
All that should amount to a repel at the very least.
The deal with GS here is simple. back face to Lao and do your forward slash as it is behind you, then use the side slash and continue to move forward without rolling, done right and you can simply beat it just waving your stick around it's chin. This should also net you a horn, watch for the break animation when it happens.
* note that tehre's also anti dragon bombs in the box for it's back