Assuming you have it set up in a vtf crosshair program go to the crosshair folder and open scripts and find what you want to change (pipebomblauncher.txt is stickies grenadelauncher.txt is pipes) Scroll to Explosion Effect for default you will change these 3
https://cdn.discordapp.com/attachments/343433678094860288/1096525780202295387/Screenshot_4.png
change the Values to look like this
https://cdn.discordapp.com/attachments/343433678094860288/1096526038697254983/image.png
That should change it to the default explosion effects