FL Studio’s Fruity Envelope Controller is an incredibly powerful tool. One of its greatest strengths is in sidechaining. 
 
While it does not process sound, its 8 articulation controllers can be used to control any parameter in FL Studio (including parameters within 3rd party plugins). Link 1 of the 8 articulation controllers on a gain, filter, wet/dry mix, or anything you want! 
 
After careful experimentation, AttaBotty created a Fruity Envelope Controller preset specifically designed for sidechaining. Articulations 1-7 are designed to be linked to FL Studio’s Fruity Balance for normal sidechaining, while articulation 8 is designed to be linked to FL Studio’s Fruity Parametric EQ 2 for sub bass sidechaining. 
 
This super useful preset is available free to download! Enjoy!