The Pilonidal Sinus is caused due to Pressure or Friction on that particular area. If it's recurring, we first of all need to diagnose the cause. Thus, I request you provide the proper case. Need to know, about your daily routine, & other things.
Next Steps
currently you can wash the area with Potassium Permanganate mixed in water (1:100).
Just add a 2-3 single particles in 1 glass of water, & wash the area.
Consult via online consultation, to take your case properly.
Health Tips
Keep the area dry, and do not try to break it yourself.