interesting question there about applied pressure causing movement such as wriggling, this is exactly what I have too when sudden activity/movement would apply to both before I started with the Albendazole and Ivermectin treatment and also during and after each course. Not sure though if the movement is entirely related to die-off as it can happen without pressure as well as with it.
As none of the anthelminth drugs work instantly or in a couple of days, it's difficult to know how long it takes to have an effect on roundworms, particularily Ascaris as they have a tough outer cuticle meaning repeated treatments are necessary. In fact during my 1st course of Albendazole the roundworms [felt like many of the adults] went frantic, like racing through the tissue, it was totally horrid to feel but I think I had some eventual die-off because of my inflamed red looking scalp which was the only area the die-off reaction showed at despite having activity in other areas. And, because of the reproduction cycles, there is always the maturing offspring to tackle again until they are all depleted, the ova, eggs through to juvenile and adult stages.
I have had them around my scalp during the last couple of months which caused an inflammatory sore scalp, the surface looked redder than other skin areas but I did not take any Antibiotics as the inflammation has now diminished. I would suspect inflammation to be the result of die-off.