On escalation, since you will eventually meet a pen that a plain flush does not fix.
A drop of dish soap in the water is the next step and it handles most stubborn cases. Rinse thoroughly afterwards — soap residue causes its own flow oddities and people then conclude the cleaning made things worse.
A pen flush solution is a step beyond that and is worth having if you own several pens.
Soaking overnight in cool water solves a surprising amount and requires no skill.
An ultrasonic cleaner — I own one and I would not recommend one to you. It is genuinely effective and it is also the fastest way to loosen a nib that was set with adhesive, damage a decorated cap, or wreck a vintage pen with a fragile sac. If you use one, it is for the nib and feed only, never the whole pen, and never with heat.
What I would avoid entirely: hot water, alcohol, and anything ammonia-based on a pen you care about. All three are recommended somewhere, all three will be fine on some pens, and all three are how people damage plastics and finishes that were fine before they started.
Since nothing is obviously wrong with yours, plain water is very likely all you need. Save the escalation for a pen that has actually stopped.