The phrase "almost ineffective" is correct and usable in written English.
It can be used to describe something that is nearly but not completely lacking in effectiveness or impact.
Example: "The new marketing strategy was almost ineffective, failing to attract the target audience as intended."
Alternatives: "barely effective" or "hardly impactful."
Insecticides selected for the protection of organic cherry orchards were almost ineffective.
Polymer mechanical degradation is found to proceed until the friction reducer is almost ineffective in reducing drag.
Simulation results prove the validity of the theoretical analysis, show that the perturbation of subarray distances can suppress the sidelobe level effectively, and the perturbation of amplitude is almost ineffective in sidelobe reduction.
Furthermore, with the growth of surface roughness, the slightly increased dryness fraction is almost ineffective for alleviating erosion caused by tiny droplets; the slight decrease in mass flow rate will reduce ejector performance to some extent, while the sharp increase of entropy generation results in more energy wastes.
The traditional systemic therapies are almost ineffective due to the blood-labyrinth barrier, which prevents the transport of drugs from the serum.
Additionally, a typical computer network at an academic institution provides a small number of mechanisms that control who exactly can access documents or internal resources -- it is a common practice to have international connections, which makes simple approaches based on geolocation almost ineffective.
At each level of assistance, almost no ineffective efforts were reported with PAV and NAVA, whereas the ineffective efforts were detected with PSV at a higher level (P <0.05).
How woefully that contrasts with the footling, pedantic and almost certainly ineffective reforms he now trumpets".
Pessimism, so obviously vindicated in retrospect, is almost always ineffective at the time.
I raised my voice at misbehaving students, trying to sound menacing, only to find that yelling was almost always ineffective.
Oil lamps, which were almost as ineffective, remained relatively unpopular until the eighteenth century, when technological innovations increased their brightness while minimizing the noxious fumes they released.
